[PATCH v3 1/2] ufs: introduce skipping manual flush for wb

[Kiwoong Kim <kwmad.kim@samsung.com>]

We have two knobs to flush for write booster, i.e.
fWriteBoosterBufferFlushDuringHibernate and fWriteBoosterBufferFlushEn.
However, many product makers uses only fWriteBoosterBufferFlushDuringHibernate,
because this can reportedly cover most scenarios and
there have been some reports that flush by fWriteBoosterBufferFlushEn
could lead to raise power consumption thanks to unexpected internal
operations. So we need a way to enable or disable fWriteBoosterEn
operations. For those case, this quirk will allow to avoid manual flush

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/ufshcd.c | 3 +++
 drivers/scsi/ufs/ufshcd.h | 5 +++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ed03051..7c79a8f 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5277,6 +5277,9 @@ static int ufshcd_wb_toggle_flush_during_h8(struct ufs_hba *hba, bool set)
 
 static inline void ufshcd_wb_toggle_flush(struct ufs_hba *hba, bool enable)
 {
+	if (hba->quirks & UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL)
+		return;
+
 	if (enable)
 		ufshcd_wb_buf_flush_enable(hba);
 	else
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index e5353d6..cfafd6e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -511,6 +511,11 @@ enum ufshcd_quirks {
 	 * OCS FATAL ERROR with device error through sense data
 	 */
 	UFSHCD_QUIRK_BROKEN_OCS_FATAL_ERROR		= 1 << 10,
+
+	/*
+	 * This quirk needs to disable manual flush for write booster
+	 */
+	UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL		= 1 << 11,
 };
 
 enum ufshcd_caps {
-- 
2.7.4